In the past years there have been many attempts to develop and test fusionless devices for correcting spinal deformities1-6. They propose a minimally invasive approach which maintains a certain spinal flexibility. Depending on the design of these implants, they engender different local stiffening of the spine.
For example, Wall et al3 introduced rigid 2 prongs vertebral staples fixed to two adjacent vertebral bodies slowing down growth on one side of the spine. They were tested on a pig model and showed the induction of significant spinal curvature (reverse problem).
Braun et al4-6 tested two different fusionless scoliosis treatments in spinal curvatures induced by an asymmetric tether in a goat model: a flexible ligament tether attached to bone anchors and a rigid-shape memory alloy staple with 2 prongs. Both systems allowed successfully correcting the deformity by growth modulation. This shape memory alloy stapling technique, with a 2- and 4-prongs design, was also used by Betz et al. in a pilot study in humans for the treatment of AIS1,2.
Previously explored solutions to hinder growth of the vertebral plate, which corresponds to epiphyseal cartilage at which new bone formation occurs to lengthen long bones during their growth phase, as an attempt to correct scoliosis include, for example, direct growth plate section using a scalpel, use of lasers to locally harm the vertebral growth plate, local inducement of a current through the vertebral growth plate to suppress growth.
Such techniques have shown their capacity to modulate the growth and correct spinal deformities. However, since they all span the intervertebral disc space, they induce changes of the spine kinematics and compression on the disc. Such effects were shown to alter the exchange of nutrients by diffusion and waste inside the disc7, and may lead to disc degeneration.
Therefore, there is a need in the art for a vertebral physeal device and method.
The present description refers to a number of documents, the content of which is herein incorporated by reference in their entirety.